Safe nursing system and method for controlling safe nursing system

ABSTRACT

A safe nursing system that monitors movement of a patient on a bed includes a control unit and an image capturing unit disposed in a position from which an image including a side of a top surface of the bed can be captured. The control unit obtains image data captured by the image capturing unit; specifies feature points in an image of the patient in the obtained image data, and calculates a value of a predetermined index of the feature points used to determine a predetermined movement in the patient; sets a predetermined condition to determine the predetermined movement based on a region of the bed in the obtained image data; determines the predetermined movement based on the calculated value and the set predetermined condition; and outputs information indicating that the patient has performed the predetermined movement under the condition that the predetermined movement has been determined to have been performed.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to safe nursing systems and methods forcontrolling safe nursing systems, and particularly relates to safenursing systems and methods for controlling safe nursing systems thatmonitor the movement of a patient on a bed.

2. Description of the Related Art

In the past, an apparatus such as a biological information monitor hasbeen used to measure vital signs such as blood pressure, bodytemperature, a cardiograph, arterial oxygen saturation, and breathingrate in order to monitor the biological state of a patient in ahospital, a household, or the like. When the measurement has returned anabnormal value, the apparatus or a remote central management apparatusto which the apparatus is connected visually and auditorily alerts adoctor or a nurse.

However, a situation such as where the patient has fallen out of his orher bed cannot be completely prevented simply by checking vital signs.

The following is an example of a sensor serving as a safe nursing systemfor preventing such falls from a bed. For example, an infrared sensor,an image sensor, or a beam sensor is an example of a sensor that doesnot come into contact with the patient. On the other hand, a floor-basedfoot sensor or a mat sensor placed under a sheet is an example of asensor that comes into contact with the patient. A clip sensor is anexample of a sensor affixed to the patient.

Such safe nursing systems can, within the sensing range of the sensors,mechanically convert the movement of the patient, such as whether or notthe patient is on his or her bed, into simplified patterns and notify acaregiver (a nurse) thereof.

However, such safe nursing systems have had problems in that finermovements of the patient (coughing, rolling over, and so on) cannot berecognized, notifications are made without determining that the patienthas moved, notifications are made after the patient has moved (forexample, after the patient has fallen out of his or her bed), and so on.

In response to such problems, a rising monitoring method and apparatushas been proposed as a safe nursing system. This method and apparatusset a monitoring region for determining whether a subject (also called a“patient” hereinafter) has risen from his or her bed, use a camera tocapture an image of a space from the side of the bed that includes themonitoring region, and determine that the subject is exhibiting risingbehavior in the case where the size of a subject image region that fitswithin the monitoring region in the captured image has become greaterthan or equal to a predetermined value (see JP 2006-175082A).

However, with the method and apparatus according to JP 2006-175082A, theimages are captured from the side, and there is a problem in that errorshave increased due to nurses entering the captured image. Furthermore,depending on the installation location, the camera has also interferedwith the nurses' work.

In addition, because the image is captured from the side, there is aproblem in that it is difficult to detect the patient moving toward aside of the bed, which is an indication that the patient will fall outof the bed. Furthermore, there is a problem that in the case where thepatient does not enter the monitoring region, such as in a case wherethe patient does not rise and instead rolls to the side and falls out ofthe bed, the patient's movement cannot be detected at all.

In addition, because rising behavior is determined based on the size ofthe patient's image region, there is a problem in that errors will occurin the determination results depending on the manner in which thepatient rises (rising behavior and how far the patient's body enters themonitoring region), differences in body shape among patients, and so on.

SUMMARY OF THE INVENTION

In order to solve the problems stated above, preferred embodiments ofthe present invention provide a safe nursing system and a method forcontrolling a safe nursing system that avoid interfering with acaregiver's care.

Another preferred embodiment of the present invention provides a safenursing system and a method for controlling a safe nursing system thatmore accurately determines a level of danger of a patient's movement.

Another preferred embodiment of the present invention provides a safenursing system and a method for controlling a safe nursing system thatmake errors caused by differences in manners of movement and patientbody shapes less likely to occur indetermination results.

A safe nursing system according to a preferred embodiment of the presentinvention includes a system that monitors movement of a patient on abed. The safe nursing system includes a control unit and an imagecapturing unit disposed in a position from which an image including aside of a top surface of the bed can be captured.

The control unit preferably includes an image capturing control unitthat obtains image data captured by the image capturing unit; acalculation unit that specifies feature points in an image of thepatient in the image data obtained by the image capturing control unitand calculates a value of a predetermined index of the feature pointsused to determine a predetermined movement in the patient; a settingunit that sets a predetermined condition to determine the predeterminedmovement based on a region of the bed in the image data obtained by theimage capturing control unit; a determination unit that determines thepredetermined movement based on the value calculated by the calculationunit and the predetermined condition set by the setting unit; and anoutput unit that outputs information indicating the patient hasperformed the predetermined movement under the condition that thedetermination unit has determined that the predetermined movement hasbeen performed.

Preferably, the image capturing unit is disposed in a position fromwhich an image can be captured from the direction of the head area ofthe patient. Further preferably, the calculation unit calculates a valueof the predetermined index for the feature points included in a regionof the head area from among the specified feature points.

Preferably, the calculation unit calculates coordinates of the featurepoints as the value of the predetermined index. The setting unit sets,as the predetermined condition, a condition for a predetermined borderto determine whether a plurality of the coordinates indicate thepredetermined movement in the patient.

Further preferably, the determination unit determines the predeterminedmovement based on whether or not an extent to which the coordinatescalculated by the calculation unit have exceeded the predeterminedborder set by the setting unit has exceeded a predetermined threshold.

Further preferably, the calculation unit further calculates a movementdirection of the feature points as the value of the predetermined index.The determination unit determines the predetermined movement based onwhether or not an extent to which the coordinates calculated by thecalculation unit have approached the predetermined border has exceeded apredetermined threshold.

Preferably, the setting unit sets the predetermined condition inaccordance with a pre-set specification method based on the position ofa side or an end of the bed.

A control method for a safe nursing system according to anotherpreferred embodiment of the present invention includes a control unitand an image capturing unit disposed in a position from which an imageincluding a side of a top surface of the bed can be captured and thatmonitors a movement of a patient on a bed.

In this control method, the control unit executes a step of obtainingimage data captured by the image capturing unit; a step of specifyingfeature points in an image of the patient in the obtained image data andcalculating a value of a predetermined index of the feature points usedto determine a predetermined movement in the patient; a step of settinga predetermined condition to determine the predetermined movement basedon a region of the bed in the obtained image data; a step of determiningthe predetermined movement based on the calculated value and the setpredetermined condition; and a step of outputting information indicatingthat the patient has performed the predetermined movement under thecondition that the predetermined movement has been determined to havebeen performed.

According to a preferred embodiment the present invention, the imagecapturing unit is disposed in a position from which an image includingthe side of the top surface of the bed can be captured, and thus doesnot capture images from the side of the bed. Accordingly, it is possibleto provide a safe nursing system and a method for controlling a safenursing system that avoid interfering with a caregiver's care.

Furthermore, because both sides of the top surface of the bed are alsocaptured, a reference value based on the sides can be set. Accordingly,it is possible to provide a safe nursing system and a method forcontrolling a safe nursing system that more accurately determines alevel of danger of a patient's movement.

In addition, the movement of the patient is determined not using arange, but by using a plurality of points. Accordingly, it is possibleto provide a safe nursing system and a method for controlling a safenursing system that make errors caused by differences in manners ofmovement and patient body shapes less likely to occur in determinationresults.

The above and other elements, features, steps, characteristics andadvantages of the present invention will become more apparent from thefollowing detailed description of the preferred embodiments withreference to the attached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram illustrating an installation position of a camera ina safe nursing system according to a preferred embodiment of the presentinvention.

FIG. 2 is a block diagram illustrating the overall configuration of acontrol apparatus in a safe nursing system according to a preferredembodiment of the present invention.

FIG. 3 is a flowchart illustrating the flow of a border conditionsetting process executed by the control apparatus according to apreferred embodiment of the present invention.

FIG. 4 is a first diagram illustrating an image captured by a cameraconnected to the control apparatus according to a preferred embodimentof the present invention.

FIG. 5 is a diagram illustrating an example of a method for specifying aborderline under a predetermined condition to determine a predeterminedmovement in a patient according to a preferred embodiment of the presentinvention.

FIG. 6 is a flowchart illustrating the flow of an alert level settingprocess executed by the control apparatus according to a preferredembodiment of the present invention.

FIG. 7 is a diagram used to set predetermined movements and alert levelson a patient-by-patient basis according to a preferred embodiment of thepresent invention.

FIG. 8 is a flowchart illustrating the flow of a movement determinationprocess executed by the control apparatus according to a preferredembodiment of the present invention.

FIG. 9 is a second diagram illustrating an image captured by a cameraconnected to the control apparatus according to a preferred embodimentof the present invention.

FIG. 10 is a third diagram illustrating an image captured by a cameraconnected to the control apparatus according to a preferred embodimentof the present invention.

FIG. 11 is a block diagram illustrating the overall configuration of asafe nursing system according to a variation of a preferred embodimentof the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Hereinafter, preferred embodiments of the present invention will bedescribed in detail with reference to the drawings. Note that identicalor corresponding elements in the drawings will be given the samereference numerals, and descriptions thereof will not be repeated.

FIG. 1 is a diagram illustrating an installation position of a camera151 in a safe nursing system according to a preferred embodiment of thepresent invention. As shown in FIG. 1, the camera 151 of the safenursing system according to the present preferred embodiment is disposedin a position from which an image of a patient 10 on a bed 20 can becaptured from the direction of the patient's head area.

Note that as long as the camera 151 is disposed in a position in whichan image including side ends (hereinafter referred to as “sides”) 23 and23 of the upper surface of the bed 20 can be captured, the camera 151 isnot limited to a position from which an image of the patient 10 can becaptured from the direction of the patient's head area. For example, thecamera 151 may be disposed in a position from which an image of thepatient 10 can be captured from the direction of the patient's feet.

Meanwhile, it is preferable for the camera 151 to be disposed in aposition from which an image including lengthwise ends (hereinafterreferred to as “ends”) 24 and 24 of the top surface of the bed 20 can becaptured.

In addition, the “patient 10” includes a person who needs to bemonitored by another person, such as a subject receiving care from acaregiver such as a doctor or a nurse in a hospital or the like, as wellas a subject receiving assistance from a caregiver in an assisted-livingfacility or the like.

FIG. 2 is a block diagram illustrating the overall configuration of acontrol apparatus 100 in the safe nursing system according to thepresent preferred embodiment. As shown in FIG. 2, the control apparatus100 preferably includes a control unit 110, a storage unit 120, anoperating unit 130, a display unit 140, an image input unit 150, anaudio output unit 160, and a communication unit 190.

The control unit 110 includes a CPU (central processing unit) and otherauxiliary circuits. The control unit 110 is programmed to control thevarious elements of the control apparatus 100, execute predeterminedprocesses in accordance with programs and data stored in the storageunit 120, process data inputted from the operating unit 130, the imageinput unit 150, and the communication unit 190, store processed data inthe storage unit 120, display processed data in the display unit 140,output processed data through the audio output unit 160 as audio, andoutput processed data from the communication unit 190, for example.

The storage unit 120 includes a RAM (random access memory) used as awork region required by the control unit 110 to execute programs, and aROM (read-only memory) to store basic programs to be executed by thecontrol unit 110. A magnetic disk (an HD (hard disk), an FD (flexibledisk)), an optical disc (a CD (compact disc), a DVD (digital versatiledisc), a BD (Blu-ray disc)), a magneto-optical disc (MO), or asemiconductor memory (a memory card, an SSD (solid state drive)), or thelike may be used as a storage medium in an auxiliary storage apparatusto complement the storage region of the storage unit 120.

The operating unit 130 includes a keyboard and a mouse, and sendsoperating signals indicating operations performed by a user to thecontrol unit 110. Instead of or in addition to the keyboard and themouse, the operating unit 130 may include another operating device, suchas a touch panel.

The display unit 140 includes a display (for example, an LCD(liquid-crystal display)). The display unit 140 displays a predeterminedimage in the display under the control of the control unit 110.

The audio output unit 160 includes a speaker. The audio output unit 160outputs predetermined audio from the speaker under the control of thecontrol unit 110.

The image input unit 150 passes image data inputted from the camera 151to the control unit 110, as well as stores the image data in the storageunit 120, displays the image data as images in the display unit 140, andso on under the control of the control unit 110.

The communication unit 190 sends information from the control unit 110to other apparatuses (for example, in the present preferred embodiment,a biological information monitor 200) via a network 900, and receivesand exchanges information sent via the network from another apparatuswith the control unit 110. Although the network 900 is preferably a LAN(local area network) in a hospital in the present preferred embodiment,the network 900 is not limited thereto, and may be another type ofnetwork, such as a network constructed over the Internet.

The biological information monitor 200 measures biological informationsuch as blood pressure, heart rate, and so on using probes attached tothe patient, and displays the measured biological information, sends thebiological information to other apparatuses via the network 900, and soon.

The camera 151 converts an image captured within an image capturingrange into image data, and in the present preferred embodiment, sendsthe image data to the image input unit 150 of the control apparatus 100.In the present preferred embodiment, the camera 151 captures movingimages. However, the image is not limited thereto, and the camera 151may capture still images in sequence over short time intervals (forexample, about every 0.1 seconds).

FIG. 3 is a flowchart illustrating the flow of a border conditionsetting process executed by the control apparatus 100 according to thepresent preferred embodiment. As shown in FIG. 3, in step S101, thecontrol unit 110 acquires, from the storage unit 120, image data thathas been inputted to the image input unit 150 from the camera 151 andstored in the storage unit 120.

Next, in step S102, the control unit 110 extracts the sides 23 and 23and ends 24 and 24 of the bed 20 from the image of the bed 20 displayedbased on the image data acquired in step S101.

FIG. 4 is a first diagram illustrating an image captured by the camera151 connected to the control apparatus 100 according to the presentpreferred embodiment. As shown in FIG. 4, the patient 10 and the bed 20are included in the image illustrated here. However, it is preferablethat the patient 10 is not present when the border condition settingprocess shown in FIG. 3 is executed.

As illustrated in FIG. 1, the camera 151 is disposed in a position inwhich both of the sides 23 and 23 of the top surface of the bed 20 canbe captured from the direction of the patient's head area when thepatient 10 is lying on the bed 20. Accordingly, an image of the topsurface of the bed 20 is included in the captured image as anapproximately trapezoidal shape. In the case where the camera 151 isdisposed along a center line in the lengthwise direction of the bed 20facing toward the center line, an image of the top surface of the bed 20is included in the captured image as an approximately isoscelestrapezoidal shape.

Meanwhile, in the case where the patient 10 is lying on the bed 20, theimage of the patient 10 is included in the captured image so that thepatient's head is toward the lower base of the trapezoid and thepatient's feet are toward the upper base of the trapezoid thatcorresponds to the shape of the upper surface of the bed 20.

The legs of the trapezoid correspond to the sides 23 and 23 of the uppersurface of the bed 20, whereas the upper base and lower base of thetrapezoid correspond to the ends 24 and 24 of the upper surface of thebed 20.

Returning to FIG. 3, in step S103, the control unit 110 calculatesborderlines 21 and 22 under a predetermined condition to determine apredetermined movement in the patient 10, based on the sides 23 and 23and the ends 24 and 24 extracted in step S102. After step S103, thecontrol unit 110 returns from the process being executed to the processthat called this process.

As will be described below with reference to FIG. 7, moving the head,attempting to rise, rising, turning over, attempting to descend (fromthe bed 20), and descending (from the bed 20) are examples ofpredetermined movements of the patient 10.

Note that moving the head can be taken as an indication that the patientis attempting to rise, an indication that the patient is rising, and anindication that the patient is turning over. Attempting to rise can betaken as an indication that the patient is rising. Turning over can betaken as an indication that the patient is attempting to descend fromthe bed 20 and as an indication that the patient is descending from thebed 20. Attempting to descend from the bed 20 can be taken as anindication that the patient is descending from the bed 20.

In other words, the patient 10 can move in the following sequence: (1)moving the head, (2) attempting to rise, (3) rising, (4) attempting todescend from the bed 20, and (5) descending from the bed 20. There arecases where the patient 10 moves in other sequences as well. The patient10 can also move in the following sequence: (1) moving the head, (2)attempting to descend from the bed 20, and (3) descending from the bed20.

In the case where the patient has safely descended from the bed 20 underhis or her own will, the movement of descending from the bed 20 issimply a movement of descending from the bed 20. However, a case wherethe patient is not moving under his or her own will and a case where thepatient has not descended safely correspond to the patient falling fromthe bed 20. In other words, the patient descending from the bed 20includes both the patient simply descending from the bed 20 and thepatient falling from the bed 20.

Meanwhile, in the present preferred embodiment, a condition in which noless than a predetermined percentage of feature points 15 assigned tothe head area of the patient 10 have passed a borderline is taken as thepredetermined condition. It is determined that the predeterminedmovement has been made in the case where the predetermined condition hasbeen met.

An algorithm such as SIFT (scale-invariant feature transform) and SURF(speeded-up robust features) can be used as the algorithm that extractsthe feature points of an object (in the present preferred embodiment,the patient 10).

However, the predetermined condition is not limited thereto, and acondition in which no less than a predetermined percentage of motionvectors of the feature points 15 of the head area of the patient 10 havepassed a borderline may be used as the predetermined condition. Vectorsindicating the amount and direction in which the feature points 15 havemoved between a predetermined number of frames in the past and thecurrent frame serve as the motion vectors of the feature points 15.

An algorithm such as the SIFT and SURF can be used as the algorithm thatcalculates the motion vectors of the feature points of an object (in thepresent preferred embodiment, the patient 10).

A condition in which a cumulative percentage of the motion vectors ofthe feature points 15 of the head area of the patient 10 are passing aborderline within a predetermined amount of time is greater than orequal to a predetermined percentage may be used as the predeterminedcondition.

A condition in which a percentage of the motion vectors of the featurepoints 15 of the head area of the patient 10 that are approaching aborderline is greater than or equal to a predetermined percentage may beused as the predetermined condition.

A condition in which a cumulative percentage of the motion vectors ofthe feature points 15 of the head area of the patient 10 that areapproaching a borderline within a predetermined amount of time isgreater than or equal to a predetermined percentage may be used as thepredetermined condition.

Although a borderline is preferably used in the aforementionedpredetermined conditions, a long, thin border region may be usedinstead, for example.

Alternatively, a condition that does not use a borderline may be used asthe predetermined condition. For example, the predetermined conditionmay be a condition in which the percentage of the feature points 15 ofthe head area of the patient 10 whose movement amounts (that is, themagnitudes of the motion vectors) are greater than or equal to apredetermined value (for example, about 20 cm) is greater than or equalto a predetermined percentage.

The predetermined condition may be a condition that the percentage ofthe feature points 15 of the head area of the patient 10 whose movementdirections (that is, the direction of the motion vectors) correspond toa direction moving away from the bed 20 or a direction moving toward aside of the bed 20 is greater than or equal to a predeterminedpercentage.

The predetermined condition may be a condition that, in the case wherethe patient 10 is close to a side of the bed 20 (for example, within therange of a predetermined distance (for example, about 30 cm) from aside), the percentage of the feature points 15 of the head area of thepatient 10 whose movement velocities (that is, the magnitudes of themotion vectors per unit of time) are greater than or equal to apredetermined value (for example, about 10 cm/second) is greater than orequal to a predetermined percentage.

Furthermore, although the aforementioned predetermined conditionsdiscuss the feature points 15 of the head area, feature points of otherareas (for example, the shoulders) may be used as well.

Furthermore, although the aforementioned predetermined conditionsdiscuss percentages that are greater than or equal to a predeterminedpercentage, in the case where the number of the feature points 15 is aset number, a number that is greater than or equal to a predeterminednumber may be used.

FIG. 5 is a diagram illustrating an example of a method for specifying aborderline under a predetermined condition to determine a predeterminedmovement in the patient according to the present preferred embodiment.As shown in FIG. 5, in the present preferred embodiment, a line withinthe trapezoidal shape that is an equal distance from the two ends 24 and24 of the bed 20 is taken as a borderline 21 for predeterminedconditions of moving the head, attempting to rise, and rising.

Meanwhile, lines within the trapezoidal shape that are equal distancesfrom a center line 25 in the lengthwise direction of the bed and therespective sides 23 and 23 of the bed 20 are taken as borderlines 22 and22 for predetermined conditions of turning over, attempting to descendfrom the bed 20, and descending from the bed 20.

FIG. 6 is a flowchart illustrating the flow of an alert level settingprocess executed by the control apparatus 100 according to the presentpreferred embodiment. As shown in FIG. 6, the alert level settingprocess is a process that sets an alert level, indicating what type ofalert to issue for a given movement, for each patient 10.

First, in step S111, the control unit 110 determines whether or not thepatient 10 in question is a patient for whom alert levels have alreadybeen set. In the case where it has been determined that the patient hasnot already had an alert level set (the case of a determination of NO instep S111), in step S112, the control unit 110 obtains biologicalinformation of that patient 10 from the biological information monitor200 via the network 900.

Next, in step S113, the control unit 110 specifies the condition of thepatient 10 based on the biological information obtained in step S112.For example, the condition is specified as poor if the blood pressure isa-b or e-f. The condition is specified as fair if the blood pressure isb-c or d-e. The condition is specified as good if the blood pressure isc-d.

Then, in step S114, the control unit 110 specifies alert levels for thepredetermined movements of each patient in accordance with the conditionof the patient 10 specified in step S113.

FIG. 7 is a diagram used to set predetermined movements and alert levelson a patient-by-patient basis according to the present preferredembodiment. As shown in FIG. 7, in the case where the patient'scondition has been specified as poor, the alert level is set to“caution” for moving the head and turning over, and is set to “warning”for attempting to rise, rising, attempting to descend (from the bed 20),and descending (from the bed 20).

In the case where the patient's condition has been specified as fair,the alert level is set to “normal alert” for moving the head and turningover, to “caution” for attempting to rise, rising, and attempting todescend (from the bed 20), and to “warning” for descending (from the bed20).

In the case where the patient's condition has been specified as good,the alert level is set to “normal alert” for attempting to descend (fromthe bed 20) and to “caution” for descending (from the bed 20).

Here, “warning”, “caution”, and “normal alert” are alerts that areeasier to be communicated to the caregiver, in that order. For example,with “warning”, an alert that combines an alarm, an output of audioindicating details of the alert, flashes a lamp, and displays textindicating details of the alert is carried out, for example. With“caution”, an alert the combines an output of audio indicating detailsof the alert and displays text indicating details of the alert iscarried out, for example. With “normal alert”, text indicating detailsof the alert is displayed, for example.

Returning to FIG. 6, after step S114 and in the case where it has beendetermined that an alert level has already been set for the patient (thecase where a determination of YES has been made in step S111), in stepS121, the control unit 110 obtains the biological information of thatpatient 10 from the biological information monitor 200 via the network900.

In step S122, the control unit 110 determines whether or not thebiological information of the patient 10 has worsened based on thebiological information obtained in step S121.

For example, using the range of blood pressures for each conditiondescribed earlier in step S113 of FIG. 3, the biological information ofthe patient 10 is determined to have worsened in the case where acondition of “good”, in which the blood pressure is c-d, has dropped toa condition of “fair”, in which the blood pressure is b-c, d-e, and inthe case where a condition of “fair”, in which the blood pressure isc-d, d-e, has dropped to a condition of “poor”, in which the bloodpressure is a-b, e-f.

In the case where it has been determined that the biological informationhas worsened (the case where a determination of YES has been made instep S122), in step S123, the control unit 110 changes the setting forthe patient 10 so as to raise the alert level set in step S114.

For example, the alert level for all movements is raised by one level.Specifically, movements for which the alert level is “normal alert” areraised to an alert level of “caution”, and movements for which the alertlevel is “caution” are raised to an alert level of “warning”.

After step S123, and in the case where it has been determined that thebiological information has not worsened (the case where a determinationof NO has been made in step S122), in step S124, the control unit 110determines whether or not the biological information of the patient 10has recovered based on the biological information obtained in step S121.

For example, using the range of blood pressures for each conditiondescribed earlier in step S113 of FIG. 3, the biological information ofthe patient 10 is determined to have recovered in the case where acondition of “fair”, in which the blood pressure is b-c, d-e, has risento a condition of “good”, in which the blood pressure is c-d, and in thecase where a condition of “poor”, in which the blood pressure is a-b,e-f, has risen to a condition of “fair”, in which the blood pressure isb-c, d-e.

In the case where it has been determined that the biological informationhas recovered (the case where a determination of YES has been made instep S124), in step S125, the control unit 110 changes the setting so asto restore the alert level, which was raised in step S123, to itsoriginal level.

For example, the alert level for all movements that was raised by onelevel is dropped by one level. Specifically, movements for which thealert level was raised to “caution” are reduced to an alert level of“normal alert”, and movements for which the alert level was raised to“warning” are reduced to an alert level of “caution”.

After step S125, and in the case where it has been determined that thebiological information has not recovered (the case where determinationof NO has been made in step S124), in step S131, the control unit 110obtains, from the storage unit 120, the image data inputted to the imageinput unit 150 from the camera 151 and stored in the storage unit 120.

Next, in step S132, the control unit 110 extracts a caregiver from theimage data obtained in step S131. In step S133, the control unit 110determines whether or not the caregiver is present.

The extraction of the caregiver is carried out by, for example,extracting the caregiver's cap above an area determined to be a headarea, and in the case where the caregiver's cap has been extracted, itis determined that the caregiver is present. Alternatively, thecaregiver may be extracted by extracting a stethoscope whose position ismoving.

Alternatively, a face included in the image expressed by the image datamay be extracted using a facial recognition technique, and it may thenbe determined that a caregiver is present in the case where theextracted face and a registered face of the caregiver match.

In the case where it has been determined that the caregiver is present(the case where a determination of YES has been made in step S133), instep S134, the control unit 110 changes the setting for the patient 10so as to lower the alert level set in step S114.

For example, the alert level for all movements is lowered by one level.Specifically, movements for which the alert level is “warning” arelowered to an alert level of “caution”, and movements for which thealert level is “caution” are lowered to an alert level of “normalalert”.

In the case where it has been determined that the caregiver is notpresent (the case where a determination of NO has been made in stepS133), in step S135, the control unit 110 changes the setting so as torestore the alert level, which was lowered in step S134, to its originallevel.

For example, the alert level for all movements that was lowered by onelevel is raised by one level. Specifically, movements for which thealert level was lowered to “caution” are raised to an alert level of“warning”, and movements for which the alert level was lowered to“normal alert” are raised to an alert level of “caution”.

After step S134 and step S135, the control unit 110 returns from theprocess being executed to the process that called this process.

FIG. 8 is a flowchart illustrating the flow of a movement determinationprocess executed by the control apparatus 100 according to the presentpreferred embodiment. As shown in FIG. 8, in step S141, the control unit110 acquires, from the storage unit 120, image data that has beeninputted to the image input unit 150 from the camera 151 and stored inthe storage unit 120.

Next, in step S142, the control unit 110 extracts feature points of thepatient 10 from the image in the image data obtained in step S141,extracts the feature points 15 of the head area of the patient 10 fromthose feature points in step S143, and calculates positions of thefeature points 15 of the head area from past images in step S144.

Returning to FIG. 4, the feature points 15 of the head area of thepatient 10 are, as indicated in step S103 of FIG. 3 and as shown in FIG.4, extracted using a conventional algorithm for extracting featurepoints of an object (in the present preferred embodiment, the patient10), after which the positions of the feature points 15 are calculated.

Proceeding to FIG. 8, in step S151, the control unit 110 executes thefollowing processes from step S152 to step S154 for the first movementof the patient.

In step S152, based on the positions calculated in step S144, thecontrol unit 110 calculates the percentage of the feature points 15 ofthe head area of the patient 10 that have crossed the borderline of thepredetermined condition corresponding to that movement. Then, in stepS153, the control unit 110 determines whether or not the percentagecalculated in step S152 is greater than or equal to a predeterminedpercentage.

For example, in the case where the patient is moving his or her head, itis determined whether or not the percentage of the feature points 15that have crossed the borderline 21 that is parallel or substantiallyparallel to the ends of the bed 20 is greater than or equal to apredetermined percentage (e.g., about 10%), and it is determined thatthe patient is moving his or her head if the percentage is greater thanor equal to the predetermined percentage.

FIG. 9 is a second diagram illustrating an image captured by the camera151 connected to the control apparatus 100 according to the presentpreferred embodiment. FIG. 9 illustrates a state in which the patient 10is partway through an attempt to rise from the bed 20.

In the case where the patient is attempting to rise, it is determinedwhether or not the percentage of the feature points 15 that have crossedthe borderline 21 that is parallel or substantially parallel to the endsof the bed 20 is greater than or equal to a predetermined percentage(e.g., about 50%), and it is determined that the patient is attemptingto rise if the percentage is greater than or equal to the predeterminedpercentage.

In the case where the patient is rising, it is determined whether or notthe percentage of the feature points 15 that have crossed the borderline21 that is parallel or substantially parallel to the ends of the bed 20is greater than or equal to a predetermined percentage (e.g., about95%), and it is determined that the patient is rising if the percentageis greater than or equal to the predetermined percentage.

FIG. 10 is a third diagram illustrating an image captured by the camera151 connected to the control apparatus 100 according to the presentpreferred embodiment. FIG. 10 illustrates a state in which the patient10 is partway through an attempt to descend from, or is near fallingfrom, the bed 20.

In the case where the patient is turning over, it is determined whetheror not the percentage of the feature points 15 that have crossed theborderline 22 that is parallel or substantially parallel to the sides ofthe bed 20 is greater than or equal to a predetermined percentage (e.g.,about 5%), and it is determined that the patient has turned over if thepercentage is greater than or equal to the predetermined percentage.

In the case where the patient is attempting to descend from the bed 20or is moving in a direction in which the patient will fall from the bed20, it is determined whether or not the percentage of the feature points15 that have crossed the borderline 22 that is parallel or substantiallyparallel to the sides of the bed 20 is greater than or equal to apredetermined percentage (e.g., about 30%), and it is determined thatthe patient is attempting to descend from the bed 20 or is moving in adirection in which the patient will fall from the bed 20 if thepercentage is greater than or equal to the predetermined percentage.

In the case where the patient is descending or falling from the bed 20,it is determined whether or not the percentage of the feature points 15that have crossed the borderline 22 that is parallel or substantiallyparallel to the sides of the bed 20 is greater than or equal to apredetermined percentage (e.g., about 95%), and it is determined thatthe patient is descending or falling from the bed 20 if the percentageis greater than or equal to the predetermined percentage.

In the case where it has been determined that the percentage is greaterthan or equal to the predetermined percentage (the case where adetermination of YES has been made in step S153), in step S154, thecontrol unit 110 communicates the movement of the patient 10 accordingto the alert level set in step S114 of FIG. 6.

For example, in the case where the alert level is set to “warning” whenthe patient is attempting to rise, an alert at the level of “warning”communicating that the patient is attempting to rise is made when it hasbeen determined that the patient is attempting to rise.

In the present preferred embodiment, for example, a “warning” that thepatient is attempting to rise sounds an alarm, outputs audio indicatingthat the patient is attempting to rise, flashes a lamp, and displaystext indicating that the patient is attempting to rise, for example.

Meanwhile, a “caution” that the patient is attempting to rise outputsaudio indicating that the patient is attempting to rise and displaystext indicating that the patient is attempting to rise, for example.Finally, a “normal alert” that the patient is attempting to risedisplays text indicating that the patient is attempting to rise, forexample.

In the case where it has been determined that the percentage of thefeature points 15 that have crossed the borderline is not greater thanor equal to the predetermined percentage (the case where a determinationof NO has been made in step S153), and after step S154, it isdetermined, in step S155, whether or not a next movement, for which adetermination of movement has not yet been made, is being carried out.

In the case where it has been determined that there is a next movement(the case where a determination of YES has been made in step S155), theprocesses of the aforementioned step S152 to step S154 are executed forthat movement. On the other hand, in the case where it has beendetermined that there is no next movement (the case where adetermination of NO has been made in step S155), the process beingexecuted is returned to the process that called this process.

(1-1) As described above, the safe nursing system according to thepresent preferred embodiment is a system that monitors movements of thepatient 10 who is on the bed 20, and includes the control apparatus 100,and the camera 151 that is disposed in a position from which an imageincluding the sides 23 and 23 of the top surface of the bed 20 can becaptured.

The control apparatus 100 obtains image data captured by the camera 151;specifies the feature points 15 of an image of the patient 10 in theobtained image data; calculates a value of a predetermined index (forexample, coordinates, motion amounts, motion directions, and motionvelocities) of the feature points 15 used for specifying a predeterminedmovement of the patient 10 (for example, the movements illustrated inFIG. 7); sets a predetermined condition to determine a predeterminedmovement based on the region of the bed 20 in the obtained image data(for example, a condition that the extent to which the coordinates ofthe feature points 15 have exceeded a predetermined border to determinethe predetermined movement has exceeded a predetermined threshold, and acondition that the extent to which the coordinates of the feature points15 have approached a predetermined border has exceeded a predeterminedthreshold); determines the predetermined movement based on thecalculated values and the set predetermined condition; and, under thecondition that it has been determined that the predetermined movementhas been made, outputs information indicating that the patient 10 hasmade the predetermined movement (for example, a warning, a caution, or anormal alert that uses a sound or a display).

In this manner, the camera 151 is disposed in a position from which animage including the sides 23 and 23 of the top surface of the bed 20 canbe captured, and thus does not capture images from the side of the bed20. Accordingly, it is possible to avoid interfering with a caregiver'scare.

Furthermore, because the sides 23 and 23 of the top surface of the bed20 are also captured, a reference value based on the sides 23 and 23 canbe set. Accordingly, the degree of danger of movements of the patient 10can be determined more accurately.

In addition, the movement of the patient 10 is determined not using arange, but by using a plurality of points. For this reason, it isunlikely that errors will appear in the determination results due todifferences in the way the patient 10 moves, the body shape of thepatient 10, and so on.

The camera 151 is preferably disposed in a position from which an imagecan be captured from the direction of the head area or the direction ofthe foot area of the patient 10. Doing so makes it possible to capturean image in which the positional relationship between the patient 10 andthe sides 23 and 23 of the bed 20 can easily be understood.

The control apparatus 100 preferably calculates values of predeterminedindices of the respective feature points 15 included in a regioncorresponding to the head area, from among specified feature points. Bymonitoring movement of the head area in this manner, it is possible tomore efficiently monitor the movement of the patient 10 than whenmonitoring movement in the entire body of the patient 10.

The control apparatus 100 preferably calculates the coordinates of thefeature points 15 as the values of the predetermined indices, and sets acondition for predetermined borders (for example, borderlines or borderregions) to determine that multiple coordinates indicate a predeterminedmovement in the patient 10 as the predetermined condition.

The control apparatus 100 preferably determines that the predeterminedmovement has been made depending on whether or not the degree to whichthe calculated coordinates exceed the set predetermined border (forexample, the percentage of the feature points 15 that have exceeded theborder in a predetermined amount of time, the cumulative percentage ofthe feature points 15 that have exceeded the border) has exceeded apredetermined threshold (for example, a predetermined percentage).

The control apparatus 100 may furthermore determine that thepredetermined movement has been made by calculating the direction inwhich the feature points 15 move as the value of the predeterminedindex, and determining whether or not the degree to which the calculatedcoordinates are approaching a predetermined border (for example, thepercentage of the feature points 15 that have approached the borderwithin a predetermined amount of time, or the cumulative percentage ofthe feature points 15 that have approached the border) exceeds apredetermined threshold.

Based on the positions of the sides 23 and 23 or the ends 24 and 24 ofthe bed 20, the control apparatus 100 sets the predetermined conditionin accordance with a pre-set specification method (for example, a methodthat takes the borderline 21 that is an equal distance from the ends 24and 24 on the head side and the foot side of the bed 20 as a border todetermine that the patient is rising, a method that takes theborderlines 22 and 22 that are equal distances from the center line 25in the lengthwise direction of the bed 20 and the sides 23 and 23 of thebed 20 as a border to determine that the patient is attempting to moveto the side of the bed 20).

The control apparatus 100 preferably sets, for each patient 10, acorrespondence relationship (for example, the correspondencerelationships indicated in FIG. 7) between a plurality of types ofpredetermined movements and a plurality of alert levels (for example,“warning”, “caution”, and “normal alert”) based on conditions (forexample, poor, fair, and good); calculates values of predeterminedindices used to determine a predetermined movement of the patient 10;sets a predetermined condition to determine a predetermined movement;determines the predetermined movement based on the calculated values andthe set predetermined condition; and outputs information indicating thatthe patient 10 has performed the predetermined movement at the alertlevel indicated by the correspondence relationship set for the patient10 in accordance with the predetermined movement, under the conditionthat it has been determined that the predetermined movement has beenmade.

In this manner, an output indicating that the patient 10 has made apredetermined movement is carried out at an alert level based on thepredetermined movement set for each patient 10, and thus a caregiver canbe notified based on the condition of each patient 10.

The control apparatus 100 preferably selects and sets the correspondencerelationship based on the condition of the patient from among pre-setcorrespondence relationships between predetermined movements and alertlevels set for the respective conditions.

Accordingly, a correspondence relationship between predeterminedmovements and alert levels can be set more easily based on the conditionof the patient 10.

The control apparatus 100 preferably specifies the condition of thepatient 10 in accordance with information from an external biologicalinformation monitor 200, for example, and selects and sets thecorrespondence relationship based on the specified condition, from amongpre-set correspondence relationships between predetermined movements andalert levels set for the respective conditions.

Accordingly, a correspondence relationship between predeterminedmovements and alert levels can be set more easily and more objectivelybased on the condition of the patient 10.

The control apparatus 100 preferably determines whether or not a valueindicated by the information from the external biological informationmonitor 200 has worsened, and in the case where it has been determinedthat the value has worsened, the control apparatus 100 changes thecorrespondence relationship so as to raise the alert levels for each ofthe predetermined movements indicated in the set correspondencerelationship.

Through these steps and functions, the settings for the correspondencerelationship between the predetermined movements and the alert levelscan be changed appropriately in accordance with changes in the conditionof the patient, which in turn makes it possible to ensure thatnotifications that predetermined movements have been made are carriedout appropriately based on the situation.

The control apparatus 100 determines whether or not a caregiver ispresent based on the obtained image data, and in the case where it hasbeen determined that a caregiver is present, the control apparatus 100changes the correspondence relationship so as to lower the alert levelsfor each of the predetermined movements indicated in the setcorrespondence relationship.

Through these steps and functions, the settings for the correspondencerelationship between the predetermined movements and the alert levelscan be changed appropriately in accordance with whether or not acaregiver is present, which in turn makes it possible to ensure thatnotifications that predetermined movements have been made are carriedout appropriately based on the situation.

The control apparatus 100 may determine whether or not a caregiver ispresent based on the obtained image data, and in the case where it hasbeen determined that a caregiver is present, may refrain from outputtinginformation.

Doing so makes it possible to avoid making unnecessary alerts in thecase where the caregiver is with the patient 10 and alerts indicatingthat the patient 10 is making a predetermined movement are notnecessary.

Next, variations of the aforementioned preferred embodiments of thepresent invention will be described.

In the aforementioned alert level setting process illustrated in FIG. 6,movements and alert levels preferably are set automatically on apatient-by-patient basis by executing the processes from step S112 tostep S114. However, the process is not limited thereto, and specifyingthe condition as per step S112 and step S113 may be carried out by adoctor or a nurse. Alternatively, the configuration may be such that themovements and alert levels are set on a patient-by-patient basismanually by a doctor or a nurse.

When a person moves, such as when rising, the person's blood pressurevalue rises. Accordingly, in the case of the patient 10 who is in dangerif his or her blood pressure is, for example, 180 mmHg, setting thedangerous blood pressure value of 180 mmHg makes it possible, in stepS122 of FIG. 6, to determine that the biological information hasworsened in the case where the blood pressure value has reached a value(for example, 160 mmHg) obtained by automatically subtracting apredetermined value (for example, 20 mmHg). The setting may then bechanged to raise the alert level before the patient's blood pressurevalue actually exceeds the dangerous value due to movement such asrising.

In this manner, it may be determined whether or not there is a risk thatthe biological information will worsen, so that an alert can be madebefore a dangerous value is actually reached.

In the aforementioned preferred embodiments, the camera 151 preferablyis disposed in a position from which an image including both sides 23and 23 of the top surface of the bed 20 can be captured. However, theposition is not limited thereto, and in the case where it is notpossible for the patient 10 to fall or descend from one side 23 of thebed, such as when the bed is pushed against a wall or a fall preventiongate is attached thereto, the camera 151 may be disposed in a positionfrom which an image including the other side 23 of the top surface ofthe bed 20 can be captured.

In the aforementioned preferred embodiments, the borderline is describedas a straight line. However, the borderline is not limited thereto, andmay be a closed-curve line or an open-curve line, such as a circle, anoval, an arc, or the like. For example, a circle of a predeterminedradius from the head area of the patient 10 in FIG. 4 may be taken asthe borderline.

Although the aforementioned preferred embodiments describes the cameraas being disposed in a predetermined position in the vicinity of the bed20, no particular mention is made of the position in which the controlapparatus 100 is disposed. Rather than being disposed in the vicinity ofthe bed 20, it may be preferable for the control apparatus 100 to bedisposed in a position that is distanced from the bed 20, such as at anurses' station or the like. Although it is not absolutely necessary tonotify a nurse, a caregiver, or the like of the patient's movement whenthe nurse, caregiver, or the like is near the patient, thisconfiguration makes it possible to notify the nurse, caregiver, or thelike that the patient is moving when the nurse, caregiver, or the likeis a way from the patient and such a notification is highly necessary.

In the aforementioned preferred embodiments, as described in step S154of FIG. 8, movement of the patient 10 is communicated at the alert levelbased on that movement using the display unit 140 and the audio outputunit 160 of the control apparatus 100 in the safe nursing system.However, the configuration is not limited thereto, and such alerts maybe carried out using a different apparatus than the control apparatus100.

FIG. 11 is a block diagram illustrating the overall configuration of asafe nursing system according to a variation of the preferredembodiments described above. As shown in FIG. 11, this safe nursingsystem preferably includes, in addition to the aforementionedconfiguration, a PC 300 and mobile telephone 400. Alternatively, onlyone of the PC 300 and the mobile telephone 400 may be included.

The PC 300 and the mobile telephone 400 preferably are connected to thecontrol apparatus 100 via the network 900. Note that the network 900 mayinclude other types of networks, such as a mobile telephone network of acommunications carrier, an internal mobile telephone network, or thelike.

In this safe nursing system, the control unit 110 of the controlapparatus 100 is programmed to control the communication unit 190 tosend, to the PC 300 or the mobile telephone 400, informationcommunicating that the patient 10 has moved, at an alert level inaccordance with that movement. Based on the received information, the PC300 or the mobile telephone 400 may then make a notification that thepatient 10 has moved, at the alert level that is set in accordance withthat movement.

Through these steps and functions, disposing the PC 300 in a positionthat is distant from the bed 20, such as a nurses' station, makes itpossible to notify a nurse, a caregiver, or the like who is away fromthe patient, and thus requires such a notification, that the patient hasmoved. Meanwhile, if the nurse, caregiver, or the like carries themobile telephone 400, the nurse, caregiver, or the like can be notifiedof the patient's movement even in the case where the nurse, caregiver,or the like is away from the bed 20.

In addition, the nurse, caregiver, or the like in charge of each patientmay be set in advance, and a notification that a patient has moved maybe made to the mobile telephone 400 carried by the nurse, caregiver, orthe like in charge of that patient. According to this configuration, thenurse, caregiver, or the like is only notified of movement of thepatients that he or she is in charge of, and is not notified of movementof patients that he or she is not in charge of. Accordingly, unnecessarynotifications can be reduced, assisting the nurse, caregiver, or thelike in executing appropriate responses.

In the aforementioned preferred embodiments, operating signals to thecontrol unit 110 are inputted from the operating unit 130, as describedin FIG. 2. However, the configuration is not limited thereto, andoperating signals may be inputted to the control unit 110 of the controlapparatus 100 from the PC 300 or the mobile telephone 400 illustrated inFIG. 11.

In the aforementioned preferred embodiments, elements that achieve thefunctions indicated in the aforementioned flowcharts preferably areconfigured virtually in the control unit 110 of the control apparatus100 by the control unit 110 of the control apparatus 100 executingsoftware. However, the configuration is not limited thereto, and theelements that achieve those functions may be configured as and performedby hardware circuits in the control unit 110 of the control apparatus100.

In the aforementioned preferred embodiments, the safe nursing system andthe control apparatus 100 included in the safe nursing system aredescribed as the present invention. However, the present invention isnot limited thereto, and can also be achieved as a control method forthe safe nursing system or the control apparatus 100 that executes theaforementioned processes using the safe nursing system or the controlapparatus 100.

The present invention can also include a control program for the safenursing system or the control apparatus 100 that executes theaforementioned processes using the safe nursing system or the controlapparatus 100.

While preferred embodiments of the present invention have been describedabove, it is to be understood that variations and modifications will beapparent to those skilled in the art without departing from the scopeand spirit of the present invention. The scope of the present invention,therefore, is to be determined solely by the following claims.

1-8. (canceled)
 9. A safe nursing system comprising: a control unitprogrammed to monitor a movement of a patient on a bed, the control unitincluding: an image capturing unit disposed in a position from which animage including a side of a top surface of the bed can be captured; animage capturing control unit programmed to obtain image data captured bythe image capturing unit; a calculation unit that specifies featurepoints in an image of the patient in the image data obtained by theimage capturing control unit and calculates a value of a predeterminedindex of the feature points used to determine a predetermined movementin the patient; a setting unit that sets a predetermined condition todetermine the predetermined movement based on a region of the bed in theimage data obtained by the image capturing control unit; a determinationunit that determines the predetermined movement based on the valuecalculated by the calculation unit and the predetermined condition setby the setting unit; and an output unit that outputs informationindicating that the patient has performed the predetermined movementunder the condition that the determination unit has determined that thepredetermined movement has been performed.
 10. The safe nursing systemaccording to claim 9, wherein the image capturing unit is disposed in aposition from which an image can be captured from the direction of ahead area of the patient.
 11. The safe nursing system according to claim10, wherein the calculation unit calculates a value of the predeterminedindex for the feature points included in a region of the head area fromamong the specified feature points.
 12. The safe nursing systemaccording to claim 9, wherein the calculation unit calculatescoordinates of the feature points as the value of the predeterminedindex; and the setting unit sets, as the predetermined condition, acondition for a predetermined border to determine whether a plurality ofthe coordinates indicate the predetermined movement in the patient. 13.The safe nursing system according to claim 12, wherein the determinationunit determines the predetermined movement based on whether or not anextent to which the coordinates calculated by the calculation unit haveexceeded the predetermined border set by the setting unit has exceeded apredetermined threshold.
 14. The safe nursing system according to claim12, wherein the calculation unit further calculates a movement directionof the feature points as the value of the predetermined index; and thedetermination unit determines the predetermined movement based onwhether or not an extent to which the coordinates calculated by thecalculation unit have approached the predetermined border has exceeded apredetermined threshold.
 15. The safe nursing system according to claim9, wherein the setting unit sets the predetermined condition inaccordance with a pre-set specification method based on the position ofa side or a an end of the bed.
 16. A control method for controlling asafe nursing system that includes a control unit and an image capturingunit disposed in a position from which an image including a side of atop surface of a bed can be captured and that monitors a movement of apatient on the bed, the method comprising the steps, executed by thecontrol unit, of: obtaining image data captured by the image capturingunit; specifying feature points in an image of the patient in theobtained image data and calculating a value of a predetermined index ofthe feature points used to determine a predetermined movement in thepatient; setting a predetermined condition to determine thepredetermined movement based on a region of the bed in the obtainedimage data; determining the predetermined movement based on thecalculated value and the set predetermined condition; and outputtinginformation indicating that the patient has performed the predeterminedmovement under the condition that the predetermined movement has beendetermined to have been performed.